A conventionally-known automatic transmission includes a planetary gear for changing a speed of driving force from an input shaft. For example, as Patent Documents 1 and 2 disclose, such planetary gear includes a pinion shaft support structure which includes pinion gears, pinion shafts which support the pinion gears, and a carrier which has shaft support holes for supporting the pinion shafts, in which the pinion shafts are supported by the shaft support holes.
In the conventional pinion shaft support structure disclosed in Patent Document 1, both ends of the pinion shafts are crimped and fixed to the shaft support holes of the carrier in a state where rotational positions (phases) of the pinion shafts are made correspond with each other. Accordingly, the pinion shafts are fixed to the carrier such that they are prevented from rotating with respect to the carrier. In the pinion shaft support structure disclosed in Patent Document 2, a part of double washers is used to prevent rotation of the pinion shafts supported by the carrier.
On the other hand, in the pinion shaft support structure disclosed in Patent Document 1, as a lubricating structure for supplying lubricant to bearings provided between the pinion shafts and the respective pinion gears, an oil guide plate is provided that is fixed to an end of the carrier, and lubricant is supplied to the bearings by the oil guide plate.